Steven Schwartzmann: The Words of Mathematics: An Etymological Dictionary of Mathematical Terms Used in English. MAA 1994, ISBN 0-88385-511-9, S. 110 (Auszug (Google))
"The notion lacks rational plausibility, having no answer to Einsteinian objections" in Brian M. Stableford: Historical Dictionary of Science Fiction Literature. Scarecrow Press, 2004, ISBN 0-8108-4938-0, S. 168 (Auszug (Google))
Elisabeth Kraus, Carolin Auer: Simulacrum America: The USA and the Popular Media. Boydell & Brewer, 2000, ISBN 1-57113-187-6, S. 126 (Auszug (Google)).
projecteuclid.org
"Philosophy of Hyperspace" - Ansprache von Simon Newcomb an die American Mathematical Society bei Project Euclid